arm64_download script - fix error starting vm twice.

platform_tools/barelinux/bin/arm64_download

 #!/bin/sh
 
 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
 usage() {
     cat >&2 <<EOF
@@ skipping 120 matching lines @@
     local working_directory="$1"
     try mkdir -p "$working_directory" || return
 
     try download_necessary_software_to_dir "$working_directory" || return
 
     try install_compiler "$working_directory" || return
 
     try install_runtime "$working_directory" || return
 
     try start_arm64_image "$working_directory" || return
-
-    try start_arm64_image \
-        "$working_directory" \
-        || return
 }
 
 for command in gsutil xz tar md5sum gunzip; do
     try command -v "$command" > /dev/null || usage || exit
 done
 
 if [ -z "$1" ] ; then
     usage || exit
 fi
 try arm64_download "$1"